40-MW(E) PROTOTYPE HIGH-TEMPERATURE GAS-COOLED REACTOR RESEARCH AND DEVELOPMENT PROGRAM. Quarterly Progress Report for the Period Ending December 31, 1962

Technical Report · Thu Oct 31 00:00:00 EST 1963

OSTI ID:4686666

The more important developments in the HTGR program are summarized. Element III-B generated a total of 225 Mw-hr of fission heat, about 30% of the heat generated by a corresponding lengih of an average Peach Bottom element in three years at 80% load factor. A series of calculations was performed to evaluate the effect on core life of changes in the core design or in basic neutron cross sections. Other calculations were performed to investigate the magnitude of flux tilts resulting from misalignment of the shim rods during normal operations. It was found that the maximum flux tilt occurs when control is being shifted from one ring of rods to another, and that this tilt would result in increases of 4% in the peak power and 8% in the integrated power in the hottest fuel elements. A study was performed to determine the effect on maximum fuel temperature of nonhornogeneous fuel loadings. Tests of a porous filter of new design show that this filter is significantly less susceptible to plugging by graphite dust than the previous filter. Nuclear calculations indicated that from a reactivity standpoint, molybdenum-sheathed thermocouples with a niobium coating would be superior to tantalumsheathed thermocouples for fuel-element applications. A test was run to determine the compatibility of this type of thermocouple with graphite and impure helium. Testing of the prototype emergency-shutdown rod- drive mechanism continued. The mechanism satisfactorily performed ten cycles under battery power against the full 10,000-lb load resistance. The installation of the transfer machine in the test facility was completed and testing was initiated. The machine successfully removed and replaced dummy fuel elements in a full-size mockup of a core segment. The analysis of samples and data obtained during in-pile-loop operation continued. Release fractions of noble-gas isotopes calculated from gas samples continue to fall quite well on extrapolated curves of release-fraction versus fuel burnup hased on previous data. Analyses of the graphite parts of element III-A indicate that these components contained only about 0.26% of the Cs/sup 137/ produced in the compacts. Studies of individual fuel particles from element III-A seem to indicate that almost all of the Cs/sup 137/ remains in the particles and that some of the Ce /sup 144/ is escaping. A study of the activities found on the second set of plateout sleeves during III-B operation suggests the possibility of barium and cesium vapor deposition. A detailed calculation of the emergency-cooling accident was completed. In addition to the determination of reactor vessel and core temperatures as a function of time, the release of isotopes of biological significance and the resulting offsite doses were determined, and the reactivity effect of the release of core poisons was calculated. (auth)

• Research Organization: General Atomic Div., General Dynamics Corp., San Diego, Calif.
• DOE Contract Number: AT(04-3)-314
• NSA Number: NSA-17-033308
• OSTI ID: 4686666
• Report Number(s): GA-4247
• Resource Relation: Other Information: Orig. Receipt Date: 31-DEC-63
• Country of Publication: United States
• Language: English

Related Subjects

REACTOR TECHNOLOGY
ACCIDENTS
ACTIVATION
ANISOTROPY
BARIUM
BURNUP
CERIUM 144
CESIUM
CESIUM 137
COATING
CONTROL ELEMENTS
CONTROL SYSTEMS
COOLANT LOOPS
CROSS SECTIONS
DEPOSITS
DUSTS
EFFICIENCY
ERRORS
FILTERS
FISSION
FISSION PRODUCTS
FUEL ELEMENTS
FUELS
GAS COOLANT
GRAPHITE
GRAPHITE MODERATOR
HEATING
HELIUM
HIGH TEMPERATURE
HTGR
IMPURITIES
IN PILE LOOPS
INERT GASES
ISOTOPES
JACKETS
MEASURED VALUES
MOCKUP
MOTION
NEUTRON FLUX
NEUTRONS
NIOBIUM
OPERATION
PERFORMANCE
PLANNING
POISONING
POROSITY
POWER
POWER PLANTS
RADIATION DOSES
RADIOBIOLOGY
RADIOISOTOPES
REACTIVITY
REACTOR CORE
REACTOR FUELING
REMOTE HANDLING
SHUTDO